hitches must be a specialty of u-haul
i was having trouble with a hitch that was installed else where and it kept coming loose!! (bummer) jk . . . but i went to u-haul and asked them a lot of questions and ended up getting a brand new hitch installed and returned the other one! i've had no issues with the hitch ever since
check out their website or give them a call i know they'll answer your questions and give you good suggestions!!